The only investors on Nest's board, often an indication of who put the most money into a company, are Google Ventures' Bill Maris and Kleiner Perkins' Randy Komisar.

Sources told both TechCrunch and Fortune that Kleiner Perkins is a big winner with the Nest sale after investing about $20 million in its A and B rounds. The reported 20-fold payout returns about 60 percent of the firm's $650 million KPCB XIV fund.

Shasta is reportedly another big winner, returning nearly all of its $250 million Shasta II fund on its Nest investment, according to TechCrunch.

Yuri Milner's Digital Sky Ventures had been expected to be the leader on that round.

But then Google apparently rode in with a barrel of cash and took Nest off the table.

The deal comes against the backdrop of a record number of venture-backed companies getting to billion-dollar valuations before going public or being sold.

Nest, which was valued at around $900 million when it raised $80 million a year ago, was on the cusp of joining that group when it decided to take Google's offer instead.

Peter Nieh of Lightspeed, who worked with Fadell at General Magic, wrote in a blog on Monday, "I had a long-standing 'joke' with Tony that whenever I would run into him, I would tell him I had Lightspeed's checkbook handy and was ready to write him a check whenever he wanted to start a company. Not sure he knew, but I was dead serious."

Nieh wrote that he and Lightspeed couldn't have been more impressed Fadell and co-founder Matt Rogers when they got the opportunity to write that long-promised check.

"We would have invested had they been looking to start a food truck," he wrote. "We had a deep belief that Tony and Matt would make something BIG happen no matter what — it would have been a game-changing food truck no doubt!"